Access Denied: System Volume Information

I am the administrator with UAC disabled (via registry)

What's the deal here? You can unhide system files but cannot edit them? Very useful, I hope I am missing something...

The "System Volume Information" folder was first introduced in Windows 2000. Even then an Administrator account had no access. At that time admin level accounts were always elevated. Even the built in Administrator account had no access. This remains the same in Windows 10.

In later versions of Windows there are other folders with restricted access.

When you consider the fact that even novices are using an admin level account granting full and unrestricted access to such an account would clearly be a bad idea. By default all software you run has the same rights the account as the users account. That means malware would also have full access.

The "System Volume Information" folder contains system restore points, previous versions of files, and other critical information. Some of this is only partially documented. Improper modification of such contents could have serious consequences.

An elevated admin account can grant themselves full access to everything if it is required. But they had better know what they are doing. Even experts can go wrong here.

Edit: Disabling UAC is a bad idea. There are many things that will not work and there may be further restrictions in later updates. This is by design and not a bug. Security will also be compromised. Using a full time administrator account may have been acceptable when XP was released in 2001. In 2017 it is just too dangerous. Windows 10 was not designed to work this way.